This invention relates to an auger system for transporting particulate material, and more particularly, to a hydraulically driven feed auger for feeding particulate material to a main auger.
Portable auger systems including a main auger tube and a hopper are well-known in the art. The hopper is connected to the lower end of the main auger tube and serves to supply particulate material to the main auger tube. More recently, side hoppers have been developed which themselves include feed auger tubes to feed the main auger tube. A lower end of the feed tube is connected to a hopper while an upper end of the feed tube is connected to the lower end of the main tube such that particulate material, received by the hopper is transported up the feed tube and then into and up the main tube. The feed tube is pivotally mounted on the main tube so that it can swing around to various positions on either side of the main tube so that the hopper can be properly positioned to receive the material to be transported. Hence, such feed auger tubes and associated hoppers are called "side hoppers" in the trade.
Portable augers for agricultural use typically have a drive shaft for coupling to a power takeoff (PTO) of a tractor vehicle for driving the main auger flight in the main auger tube by direct mechanical connection. The feed auger flights have been driven by a variety of different arrangements. For example, feed auger flights have been driven mechanically with an array of drive lines and U-joint, a set of gears and U-joints, or a hydraulic motor powered by the hydraulic system of the tractor. Where the tractor's hydraulic system is employed, that system must have an adequate capacity to operate the hydraulic motor(s) of the auger(s)
U.S. Pat. No. 4,963,066 to Boppert describes separate driving of the main auger flight and the feed auger flight, the feed auger flight being driven by hydraulic motors powered by the hydraulic system of the tractor. This arrangement necessitates the use of the auger with a tractor having a hydraulic system of adequate size. If the tractor does not have an appropriate hydraulic system, the Boppert system is unusable.
U.S. Pat. No. 5,094,334 to Bobrowski describes a main auger flight powered by the PTO shaft of the tractor, with the feed auger flight mechanically driven by gears and U-joints coupled to the main auger shaft. Since there is a fixed drive between the main auger flight and feed auger flight, the user has no separate control over the two drives and thus no ability to permit stopping of the feed auger to clear the main auger.
Prior gear and mechanical systems required lubrication which added the risk of excess lubrication oil being leaked into the grain, thereby contaminating the grain and occasionally restricting grain flow, thereby diminishing the effectiveness of the auger. Further, such systems often ran hot, creating risk of grain fires. Hydraulic systems are better than gear and mechanical drive systems, but repeated connection of the hydraulic hoses from the tractor's hydraulic system tended to wear seals in the connections, leading to leaks of hydraulic fluid into the grain.